Datagrid is something you`ve probably encountered multiple times in user interfaces. It`s a component that displays data in the form of a table. So if you are looking for Javascript libraries with spreadsheet functionality like copy paste, move around in cells with keyboard, parse and read excel files, etc then you might want to consider these Javascript plugins and libraries.

x-spreadsheet

A web-based JavaScript spreadsheet.

SheetJS js-xlsx

Parser and writer for various spreadsheet formats. Pure-JS cleanroom implementation from official specifications, related documents, and test files. Emphasis on parsing and writing robustness, cross-format feature compatibility with a unified JS representation, and ES3/ES5 browser compatibility back to IE6.

SlickGrid

SlickGrid is a fully open-source, javascript, client-side grid control, based on jQuery and jQueryUI and compatible with Bootstrap.
The grid is designed to take an external component as a datasource, and that means SlickGrid should be compatible with a wide range of modern data-centric frameworks.

Handsontable

Handsontable was a perfect fit because it looks and feels just like Excel, a tool teachers are already familiar with.

React-Datasheet

A simple react component to create a spreadsheet.

Jexcel

Jexcel is a very light jquery plugin to embed a spreadsheet compatible with Excel in your website or application. You can create a excel-like table from a JS array, json or even a CSV file. You can use your copy and paste shortcuts to move data from excel straight to your jExcel spreadsheet and vice versa. You can easily integrate third party jquery plugins to create your own custom colums, custom editors, and customize new features to your clients. jExcel has a plenty of nice features such as key-value dropdown, CSV loading/exporting, multiple spreadsheets and much more.

ipgrid

Ip.grid is a fully fledged native jQuery spreadsheet plugin, designed to look and feel like Google sheets. And as far as I know, is the most comprehensive spreadsheet plugin on the net.

WickedGrid

Easy & Wicked Fast spreadsheets for the web.

Sheetsee.js

Sheetsee.js is a client-side library for connecting Google Spreadsheets to a website and visualizing the information with tables and charts.

Sheetrock

Sheetrock is a JavaScript library for querying, retrieving, and displaying data from Google Sheets. In other words, use a Google spreadsheet as your database! Load entire worksheets or leverage SQL-like queries to sort, group, and filter data. All you need is the URL of a public Google Sheet.

Cheetah Grid

It is the fastest open-source data table for web.